What you guys have posted
is pretty much right, especially if the new cue has the same shaft type, ferrule, and tip as the old cue. What I have found out with my first custom cue was the cue felt 'good' to start with, but to get to 'really good' took about 3-4 weeks of playing with it. And then playing with it over time, you learn the sutble nuances the stick has, like shooting force follow shots, can you get the draw spin on shots, and little things like that. I think the player adjusts to the new cue unless there is a factor in there that they can not get past, for example, if the new cue's balance is much different than the old cues balance.
I shot with a 21 oz. cue for years and years, when I got my first custom, I went to 20.3 oz, forward balanced, and I adjusted to it, and it began to feel better to me, and I noticed on certain shots I was getting better results. I have shot with a 19 oz cue for about 8-9 years now, and I have adjusted to it, with my speed on shots down pretty good. Getting another custom made in February, and I want it to be 19 to 19.3 oz, forward balanced.
I can pick up a friend's cue or just another cue though, hit about 6 shots with it, and tell you exactly what is wrong with that cue for me, and I just mean for me, whether it is the hit, the tip, the taper, butt size, or balance.
For example, I have hit with a few Jacoby's trying them out, and they felt pretty good, but the balance was not quite right for me. It seemed like there was a little too much weight at the top part of the handle, and not distributed evenly, and forward balanced, or I would have bought one in the past.